Sick or tight building syndrome is a term that describes from the ill effects building occupants suffer due to poor indoor air quality. Although not attributed to any specific disease (SBS), leads to a loss of employee productivity.
An extensive list of symptoms related to (SBS) include:
- eye, nose or throat irritation
- dry cough, dry or itching skin
- difficulty in concentration
- sensitivity to odors
- hoarseness of voice
- cold, flu-like symptoms
- increased incidence of asthma
- shortness of breath on mild exertion
- pregnancy problems and miscarriages
- Legionnaire’s disease
- humidifier fever
- pneumonia and occupational asthma
- chest pain
Building air vents and windows are another channel in which vehicle exhaust and other pollution can enter the space. Secondary combustible products can enter the building through nearby sources. Formaldehyde, radon, asbestos, dust and lead paint can enter the structure through various means.
Indoor Sources: volatile organic compounds are the most common indoor air contaminants. Carpets, tapestries, copiers, manufactured wood products, pesticides and cleaning agents are the main sources of VOC’s. Thus, environmental tobacco smoke, adhesives, breathable particles, combustion products from the stove, fireplace and unheated heater also increase chemical contamination.
Biological Contaminants in Sick Building Syndrome
Biological contaminants include pollen, fungi molds, bacteria, and fungi. Bio-contaminants such as these grow in stagnant water accumulating in humidifiers, drains or anywhere that moisture has infiltrated fabrics of insulation.
Bird and insect droppings is yet another source of bio-contamination that lead to Sick building syndrome. Besides, this type of pollutant can cause fever, chills, coughing, chest tightness, muscle aches, and allergic reactions. When employees are working in tight quarter’s, the spread of airborne illnesses can be spread quickly between persons. Therefore, air conditioning systems can further exacerbate the problem by recirculating the polluted air throughout the building.
The oil embargo of 1973, pressed construction firms to create buildings more airtight, and with less ventilation to improve overall energy efficiency. The result has been that there is now less CFM per person in buildings than ventilation rates recommended by current ASHRAE 62.1-2016 standards.
Furthermore, poor performance of HVAC units is worsened by filter maintenance failing to meet recommended schedules.
Microwaves, TVs, and computers emit electromagnetic radiation that ionizes the air. Similarly, if electrical cables are improperly grounded, they create powerful magnetic fields in which cancer has been linked.
PREVENTION AND CONTROL
Current commercial buildings include design that includes energy efficiency as a top priority. For example, new construction techniques and materials used for the shell of the building minimize heat gains and losses. Also, this prevents the unwanted infiltration of moisture-laden outside air from entering the space, thereby decreasing the cost of space conditioning.
To maintain the latest ASHRAE ventilation requirements, owners/operators of commercial buildings generally have to depend on up-sized packaged rooftop HVAC systems not only to condition the recirculating air but to also bring in fresh OA to meet IAQ requirements. This results in larger equipment investments and higher operating costs.
A simplified Approach
A 100% dedicated outside air system from United CoolAir Corporation provides a simplified more effective solution. A DOAS unit works in conjunction with a sensible heating/cooling system. Furthermore, 100% outside air units such as Alpha Aire and OmegaAir, are stand-alone systems designed to meet the todays OA requirements. Traditional HVAC systems are primarily built to handle design sensible loads; However, they are inadequately designed for the high latent loads produced by outside air. UCA DOAS units are designed exclusively to handle a large latent ventilation load. This in turn delivers “neutral” air of 72°F to 75°F @ 50% RH.
DOAS units supply air dew point design temperature is lower than standard air conditioners to remove the maximum amount of moisture before delivery to the space.
By separating the sensible load from the latent load, the Outside air unit removes the moisture from its primary source and fresh outdoor ventilation air at the lowest cost. Units can further assist the main space-conditioning unit by handling some of the smaller internally generated amounts of latent and sensible loads that naturally build from occupants and other sources. As a result you can achieve a better IAQ at a lower cost with healthier buildings.